Rather than use the much vaunted 'pattern makers dowels' or a  commercial means of repeatedly joining base board edges in register, I  offer the following method. No components can be lost or mislaid, making  it ideal for a travelling layout.

 You'll need a suitable 'bolt' and 'nut', a length of  wire coat  hanger, some scraps of concentric copper tubing and a few washers and  screws. If you can't find suitable copper tube then consider 'slip  couplings'.

 Standard couplings have a ridge in the centre which lets pipe enter  only halfway.  The slip coupling does not have a ridge so it can move  freely wherever you need it, and makes an ideal means of lining a hole  in a base board end member so that a piece of plain pipe slides  accurately inside. They are available in various sizes at plumbers'  merchants.

 The nut and bolt I have chosen are an 8mm nut soft soldered to a 25mm  washer, and for a bolt, the type of screw fitting used to hold head  boards to divan beds, usually free for the asking at bed and furniture  stores as long as you phrase your request suitably!

 The 'nut' soldered to a washer is screwed to the inside of one end  member, but only loosely, as a little free play will facilitate easy  screw insertion. The copper aligning pipe slides in and out and a small  raised portion stops it falling outwards whilst the coat hanger wire  stops it falling inwards, it cannot be lost or mislaid.  A screw mounted  upon washers stops the screw member being lost by falling inwards.
 The adjacent end members of the base board frame are clamped together  whilst the screw and copper tube holes are drilled, before frame  assembly, ensuring perfect alignment.
Despite over 40 years of woodworking experience I blanche at the the  thought of retrospectively fitting 'Pattern Maker's Dowels' to a  completed framework to secure perfect alignment. They are best used to  accurately mate two parts of a component before they are worked  upon to be incorporated in a pattern. In the ordinary course of events a  male member is left to protrude vulnerably whereas this suggestion  allows both elements to withdraw safely leaving a smooth face to the  framework.












I've shown my use of concentric copper pipe before on Bear's End, but before I hit on the idea of coat hanger wire to keep the inner tubes from being lost, and washers to stop the bolt elemnts from dropping out.

 I hope this helps,
  
 Doug

Hi Doug,

I like those oversize hand knobs - plenty of torque and no need for spanners/sockets (and smooth edges as well - bonus!). I shall them in mind for the home modules. The club modules are another story.

Nigel